Inclusion Criteria:

1. Male and female subjects with histologically documented resectable rectal
adenocarcinoma in stage II-IV.

2. Availability of tumor biopsy sufficient for immunological analysis.

3. Indication to receive neoadjuvant concomitant chemoradiotherapy consisting of a
radiation dose of 45-52 Gy and capecitabine 825 mg/m² orally twice daily. The use of
an equivalent schedule based on 5-fluorouracil (5-FU) is acceptable.

4. Imaging not older than 4 weeks to document absence of metastatic disease.

5. Eastern Cooperative Oncology Group (ECOG) performance 5. status of 0 or 1.

6. Written informed consent.

7. 18 years of age.

Exclusion Criteria:

1. Previous chemotherapy and/or previous radiotherapy of the pelvic region.

2. Relapsing disease.

3. Previous vaccination with any MUC1 vaccine and other therapeutic cancer vaccines.

4. Previous organ transplantation (bone marrow or solid organs).

5. Subjects with metastatic disease (except for solitary, resectable liver or lung
metastases).

6. Inadequate hematological function (i.e. platelet count < 140*10^9/L, or WBC <
2.5*10^9/L, or hemoglobin < 90 g/L). Clinically significant hepatic dysfunction (i.e.
alanine aminotransferase [ALT] > 2.5 times upper limit of normal [ULN], or aspartate
aminotransferase [AST] > 2.5*ULN, or bilirubin > 1.5*ULN). Inadequate renal function
(i.e. serum creatinine > 1.5*ULN).

7. Autoimmune diseases.

8. Recognized immunodeficiency disease including cellular immunodeficiencies,
hypogammaglobulinemia or dysgammaglobulinemia; subjects who have hereditary or
congenital immunodeficiencies.

9. Any preexisting medical condition requiring chronic steroid or immunosuppressive
therapy.

Additional exclusion criteria also apply.